<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>盒子边框线</title>
    <style>
      .box {
        width: 250px;
        height: 300px;
        background-color: pink;
        box-sizing: border-box;
        
        /* border: 1px solid #000; */
        /* border: 5px dashed red; */
        border-left: 2px dashed red;
      }
    </style>
  </head>
  <body>
    <div class="box"></div>
  </body>
</html>
